Apparatus for truncating cups



Dec. 9, 1958 E. "r. ALDINGTON 2,853,366

I APPARATUS FOR TRUNCATING CUPS 4 Filed Nov. 22, 1955 United States Patent APPARATUS FOR TRUNCATING CUPS Elmer T. Altlington, Bethlehem, Pa., assignor, by mesne assignments, to American Can Company, New York, N. Y., a corporation of New Jersey Application November 22, 1955, Serial No. 548,339

1 Claim. (Cl. 93-36.1)

This invention relates to a method of and apparatus for truncating the apex or bottom of a conical paper cup, and this application is a continuation in part of application Serial No. 468,715, filed November 15, 1954 and now abandoned.

Attempts have been made and various forms of apparatus have been developed for the purpose of truncating or blunting the apexes of conical paper cups. However, such attempts have not been entirely satisfactory since the folds or creases in the truncated bottoms have been uneven and unattractive in appearance and have been subject to sagging or opening up or leaking due to the weight of the liquid in the cup. Moreover, intricate and complicated apparatus has been required to control the formation of the truncated bottom.

This invention has for its salient object to provide apparatus for and a method of truncating a cup apex by so applying the compressing force to the apex that folds in the cup wall will be formed evenly and naturally and there will be no tendency for the apexial wall to buckle.

Another object of the invention is to provide a conical cup apex and truncating means therefor so related that the truncating or compressing force will be applied to the cup in such a manner that the folds in the wall will be formed evenly and naturally and there will be no tendency for thewall to buckle during the truncation thereof.

Another object of the invention is to provide a conical cup and truncating mechanism therefor so designed and so interrelated that the compression of the cup apex will form even, natural folds substantially concentric with the cup axis and will not buckle the cup wall.

Further objects of the invention will appear from the following specification taken in connection with the drawings which form a part of this application, and in which Fig. 1 is a plan view showing diagrammatically a plurality of blank shapes designed to form a conical cup of such a shape as to facilitate the truncation or blunting of the cup apex;

Fig. 2 is an elevational view of a conical cup formed from one of the blank designs illustrated in Fig. 1;

Fig. 3 is a diagrammatic illustration showing the cup mandrel, clamp and punch adapted to be used in carrying out the method;

Fig. 4 is an enlarged sectional elevation illustrating, in section, the outer edge portion of the truncated cup and contacting portion of the punch face; and

Fig. 5 is a diagrammatic elevation showing, in section, the component forces set up between the punch face and the cup wall when these parts are not properly designed.

In the particular embodiment of the invention illustrated, Fig. 1 shows a cup blank having an arcuate edge 11 which forms the open end of the cup, an edge 12 which forms the inside seam line of the cup when the blank is folded, and a series of edges designated A, B, C, D and E which are adapted to form the outside seam line when the blank is folded, the edges A, B, C, D and E representing alternative constructions. It will he understood that the use of the particular edge A, B, C, D or B will be determined by the amount of overlap desired and the thickness desired for the: apex portion of the cup.

Each of the edges A, B, C, D and E, as shown, has a relatively straight portion 13 which extends from the arcuate edge 11 inwardly to a curved portion 14. If desired, the curved portion could be straight, as shown in dotted lines at 15. For the efficient folding of the cup wall during the truncating cup operation in such a manner that the wall will not buckle, it is essential that the portion of the outside seam line disposed Within the apexial portion of the cup to be truncated be substantially perpendicular to the fold lines in the cup wall which are shown in dotted lines on Figs. 1 and 2 and are designated 21, 22, 23, 24 and 25. It will be noted that the fold lines on the cup wall are disposed in planes substantially perpendicular to the cup axis and it is essential for efiicient folding that this relationship be maintained. If the inside seam line is not perpendicular to the fold lines, the folding will take place on a diagonal radial plane and the cup wall will buckle.

It has been found that in order to efficiently truncate the cup wall at the apexial portion of the cup without having the wall buckle and without requiring complicated and intricate control mechanism that the punch face which contacts the apex and successively contacts the wall of the cup should be disposed substantially at right angles to the wall of the cup.

In Fig. 3 there is shown a mandrel or die 30, a clamp 31 for clamping the cup 32 to the mandrel or die 30, and a punch 33 slidable in the clamp 31 and having a face 34 engageable with the apex and with the cup wall to form successive folds or creases therein. The punch has a central V-shaped recess 36 in its bottom surface to receive the apex of the cup and center the cup.

It should be noted that the punch face 34 is disposed substantially at right angles to the cup wall during the truncating operation. Thus, the compressing force of the punch against the cup wall has no component of force which would tend to buckle the wall.

In Fig. 5 it will be noted that the face 34A of the punch is not disposed at right angles to the wall 35 of the cup. Thus, there is a component of force shown by the arrow X which tends to force the cup wall 35 to the right or to buckle the wall.

It will be understood that after the apex of the cup has been truncated in the manner above described, the shape of the cup bottom can be changed by finishing dies.

Although one specific embodiment of the invention has been particularly shown and described, it will be understood that the invention is capable of modification and that changes in the construction and in the arrangement of the various cooperating parts may be made without departing from the spirit or scope of the invention, as expressed in the following claim.

What I claim is:

In combination, means for clamping a conical paper cup in such a manner as to avoid buckling of the paper wall during a truncating process, said clamping means having a conical clamping surface with the apex of the cup projecting beyond the clamping surface, a punch having an axis alined with the axis of the clamping means and having a depending conical surface adapted to engage the apex of a cup and said conical surface being at substantially right angles to the wall of a cup during a truncating operation.

References Cited in the file of this patent 

